The present exemplary embodiments relate to replaceable consumables holding marking material and, more particularly, to replaceable consumables holding marking material and including processors having internal logic gates which are configurable to adapt the cartridge for interaction and use with a wide variety of marking machines such as printers and the like. The present exemplary embodiments of circuits with processors having configurable logic find particular application in conjunction with ink jet cartridges and toner cartridges, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiments are also amenable to other applications such as, for example, anywhere replaceable consumables are used together with devices or systems dispensing consumable materials during manufacturing operations or any other industrial, commercial or clinical or medical processing operation.
In connection with printing words and images on paper, it is important for proper operation of the printing device that compatible replaceable consumables are used. More particularly, many printers are developed using hardware and the like designed to operate with particular ink or toner formulations. Also, mechanisms provided in the printer for even, smooth, and efficient delivery of marking material to the printhead portions of the printer require corresponding structures on the replaceable consumables. These may include specialized ports or valving in ink cartridges or gears and other drive mechanisms in toner cartridges for example.
Thus, there may be a legitimate need in the art for printing devices to interrogate replaceable consumables in the form of ink cartridges and/or toner cartridges for information relating to compatibility of the cartridges and their contents with the printing device. Printheads on some ink jet printers become destroyed if printing operations are continued beyond the quantity of ink contained within the replaceable cartridge. Accordingly, the quantity of marking material contained in the replaceable consumable is, at times, useful information.
Other information relating to the marking material might be important as well such as information relating to ink or toner formulations. In some cases, various electrical and mechanical parameters are determined internal to the printer based upon information relating to properties of the marking material. Examples include pulse width and voltage levels for firing ink jet nozzles based upon certain parameters of the ink marking material contained within the consumable cartridge. Cartridge manufacturers can accommodate new ink formulations in old printers by simply providing updated ink parameters data in the electronics carried on the cartridge.
Accordingly, for various business and technical reasons, original equipment manufacturers OEMs have provided electronics on replaceable consumables. Strategies with regard to implementation have included vastly different solutions. At one extreme, manufacturers have adopted application specific integrated circuit (ASIC) devices to carry information on the consumable cartridge. Others have adopted a universal approach by providing programmable microcontroller units (MCU) electronics on the cartridges.
ASICs include memory portions and read and write controllers adapted to communicate data between the associated printer and the memory portion of the cartridges. Ink quantity information, date of manufacture, ink quality and manufacturer information may be included in the memory portion of the ASIC. The ASIC is selectively interrogated by the printer for providing information to the printer. Also, as ink is consumed by the printer, the ink quantity information is selectively updated by writing data to the ASIC.
Those skilled in the art will appreciate that ASIC devices have a large initial cost in non-recurring engineering. ASIC design is inflexible and, once set, cannot be easily modified without incurring additional expenses. It is difficult for original equipment manufacturers to extend a single ASIC design across multiple cartridge applications because each ASIC design is typically specific to a particular cartridge type. Any changes in the cartridge specification such as changes in ink capacity, ink performance parameters, and the like cannot be accommodated without a redesign of the ASIC. These changes may become necessary in order to take advantage of new ink technologies for example or when safety or health compliance concerns affect existing ink technologies.
A more general solution has been proposed in the form of the MCU technology which typically includes a general purpose processor, a memory portion, a read and write controller and a fixed internal instruction set which can be utilized by the processor by constructing a written program for writing data to the memory portion and for communicating the data between the replaceable consumable and the printing device.
The processor in a typical MCU includes a set of preconfigured instructions to execute a predetermined set of instructions in the form of op codes. To reduce costs and increase speed, reduced instruction set cartridges (RISC) have been developed. The op code set provides basic instructions for processing the ink cartridge data received from the printer and for receiving cartridge data between the internal memory portion and the associated printing device as needed to support printing operation.
One disadvantage of the MCU/RISC technology is that the processor is only capable of executing op codes provided for by the MCU/RISC vendor. Therefore, the MCU operation cannot be optimized by the cartridge vendor to provide or perform special data operations. At times, the software in the MCU will be unable to keep pace with the timing required by the associated printer. The op codes and predetermined instruction set regardless of the on-board program may not be able to execute at a rate sufficient to keep pace with the printer communication interface protocol leading to a printer fault or a cartridge malfunction. Although the program can be changed to adapt MCU to changes in the cartridges, the cartridge vendor is constrained to program the MCU with the limited op code set provided from the vendor. In addition to the above, MCU/RISC technology is relatively expensive because, as noted above, the technology proposes a general solution for all applications rather than a specific solution narrowly tailored to specific printer types or product lines.
Therefore, there is a need in the industry for a replaceable consumable in the form of ink jet or toner cartridges carrying electronics including programmable logic devices which can be easily programmed after fabrication of the device but without the constraints of predefined op codes. A PLD, unlike an ASIC, can be programmed after it is manufactured. Also, a PLD can be programmed using any form of logic as desired unlike the MCU/RISC technology which relies upon predefined internal logic and op codes.